The spotter is a helper who gives the shooter guidance on how to hit a particular target.
In some cases the spotter may just report the location of the bullet impact. In other cases they may judge the speed and direction of
the wind, determine the range, and give the shooter the settings to be used on the sights.

The distance, or clearance, between the base of a chambered cartridge and the breech face (or bolt face) of a firearm.
This is a critical dimension, particularly in high powered rifles. If there is too little headspace, the bolt will not close.
If there is too much headspace the cartridge will not be properly supported in the chamber and the cartridge will expand upon
firing and may rupture, blasting high-pressure gas into the action and possibly into the body of the shooter.
Headspace should be .003" - .006" in a centerfire rifle. It can be checked with a set of "Go and No-Go"
gauges specific to the calibre in question. (See below.) With a standard cartridge, the headspace is
registered by the shoulder, with a belted cartridge, the headspace is registered by the forward edge of the belt.

A type rimfire rifle cartridge developed by the ammunition company Hornady.
.17 Hornady Magnum Rimfire (4.5×27mmR), commonly known as the .17 HMR, was developed in 2002.
It descended from the .22 Magnum by necking down the .22 Magnum case to take a .17 caliber (4.5 mm) bullet.

An attachment to or integral part of the barrel that redirects some of the pressurized gas that propelled the bullet out
the muzzle to the sides and possibly rearwards from the direction of the bullet travel. This reduces the recoil of the firearm.

Italian for "short." Seen as part of a cartridge designation. On some Italian manufactured guns that use .380 ACP, the designated caliber is 9mm Corto (9mm Short), which is also the same as the German 9mm Kurtz

On a revolver, a spring activated device housed in the bottom of the frame beneath the cylinder that engages alignment notches in the cylinder.
It stops the cylinder's rotation and holds it in place each time a chamber in the cylinder is in alignment with the barrel.

A term often used to refer to the very poor and dangerous practice of rapidly firing many shots at a target as
possible in the hope that one or more may hit the target. This practice is a danger not only to bystanders but also to the shooter.

A variety of pneumatic gun that propels projectiles by means of compressed air or other gas, in contrast to firearms, which use a propellant charge.
Both the rifle and pistol forms (air rifle and air pistol) typically propel metallic projectiles, either pellets, or BBs. Certain types of air guns, usually rifles, may also propel arrows.

The front sight is placed at the muzzle end of the barrel. It is often (but not always) in the form of a dot or a blade.
To attain a proper sight picture and shoot with the greatest degree of accuracy, the shooter's eye
should be focused sharply upon the front sight while shooting, allowing both the rear sight and the target to blur somewhat.

A style of rear sight, typically used on rifles for either slow-moving bullets or for long ranges, whereby a ladder may be raised from
flush with the barrel to a vertical position, and which incorporates a sliding crossbar which may be moved vertically in order to achieve significant elevation.